Characteristics of peats of the southern taiga in the southeast of West Siberia as a basis for carbon stocks assessment in peat deposits

Abstract

The aim of the study. To identify regional and zonal features of peat properties and the degree of influence on them of paleocryogenic processes, as a basis for correct paleoreconstructions of the functional state of mires and carbon stocks assessment in peat deposits in the study area.

Location and time of the study. Subzone of the southern taiga within the Tomsk region, Russia.

Methods. Using the database developed for the "Peat deposits of Tomsk region" cadastre and the archived materials of peat deposits geological exploration, the selection of peat deposits and types of peat typical for the study area was carried out, and the indicators of their occurrence, average degree of decomposition, ash and moisture content were calculated. To identify regional and zonal peat properties, a comparison with the similar characteristics of peats in the European part of Russia was conducted. To substantiate the cryogenesis of peat properties, the literature data about the effect of permafrost on the dynamics and properties of peat mires in the cryolithozone, alongside with the previously obtained data on the reconstruction of paleocryogenic processes in the thoroughly studied and dated peat sections of the study area, were used.

Results. For 21 identified typical types of peat, the known regional and zonal features of their properties were established or confirmed. The determining influence of seasonal permafrost and paleocryogenic processes on the botanical composition and occurrence of peat types, on significant variation in their properties, unusually high ash content of fen and transitional peats, low average degrees of decomposition and high values of the studied properties in other types of peats, secondary changes in peat properties and specifics peat deposition in the deposits was substantiated. The species composition of the working collection of peat samples from the study area for assessing their carbon content was chosen.

Conclusions. Due to the significant influence of paleocryogenic processes on peat properties, it is necessary to take the processes into account in order to improve the interpretation of data obtained during studies of mires for solving various scientific and applied problems, including assessing carbon balance and reserves in mire ecosystems. The data about peat occurrence and properties, obtained for peat deposits of different types, allow an objective approach to developing a working collection of peat samples to assess peat carbon content in the study area.